Use the 24 hour clock.
Give times in the local time zone.
Always show two digits for the hour and two digits for minutes using a colon as the separator; eg: 09:00, not 09.00 nor 09-00 and not just 09 and never 09:0 or 9:00.
Time ranges use a hyphen as the separator between the two times and are unspaced; eg: 09:00-17:30
Where an establishment does not close on a particular day or range of days, write 24 hours, not 00:00-24:00. If the establishment doesn't close all week: 24/7
As an alternative, a 12 hour, am/pm format may be used consistently in any destination article where the 24 hour format is locally very rarely seen in print; eg: 10:30am-5pm.
Choose to deviate from our standard, 24 hour format only to follow overwhelming local written usage. Ask yourself: "which format will visitors see in newspapers, on shop doors, and on train schedules?" If the answer is "a mixture", then use our standard 24 hour format.
Only in this alternative am/pm system, use "noon" and "midnight", not 12am and 12pm.
Only in this alternative 12-hour format, minutes are not shown when not required, eg: 5pm, not 5:00pm.
Spaces and periods (full stops) should be left out, eg: 10:30am-5pm, not 10:30 A.M. – 5 P.M.
Spaces should be left out for noon and midnight too, eg: 10am-noon.
No single article should mix the standard 24 hour format with this alternative 12 hour variation.
Abbreviate to the minimum number of letters for clarity: M Tu W Th F Sa Su, especially in listings, but
spell out if it looks odd or ambiguous in a particular context or when it is part of a named day, eg: "Good Friday", "Fat Tuesday".
a range of days is shown with a hyphen: eg: M-Th specifies Monday and Tuesday and Wednesday and Thursday.
spaces should be left out, eg: M-Fnot M - F or M thru F.
also include the dash for a pair of consecutive days, eg: Su-Mnot Su M.
for a list of days that are not in a range, separate the day abbreviations with commas; eg: when a shop is open on Monday, Wednesday and Friday but closed on Tuesdays and Thursdays write Mo,W,F 08:30-17:30
when combining days or months with time, put the months first, then days and finally the times eg: May-Sep M-F 10:00-14:00rather than 10:00-14:00 M-F May-Sep.
when listing alternative ranges (for example, seasonal opening hours) separate the alternatives with a semi-colon eg: Hall of Mirrors 3 May-8 Sep M-Sa 08:30-18:00; 9 Sep-2 May Th-Sa 10:30-16:00. Horror Maze May-Sep M-Sa 08:30-18:00; Oct-Feb F-Sa 10:30-13:00;
for all seven days, use Daily. Do not use "every day" or "Su-Sa".
Use the date format of dd mm yyyy, eg: 10 Jan 2003.
Abbreviate months to three letters: Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec, especially in listings, but
if it looks odd or ambiguous in a particular context, spell it out.
avoid using dates such as 10/1/03, 10-1-03 or 10/1/2003 as this can mean 10 Jan 2003 or 1 Oct 2003 to different people!
By default, years are numbered according to the Western Dionysian era (also referred to as the Common Era) and the year is assumed to be AD (or CE).
This means that in the phrase "Queen Victoria died in 1901", it is unnecessary to write either "Queen Victoria died in 1901 AD" or "Queen Victoria died in 1901 CE".
For years earlier than 1 (AD or CE), that year is followed by the two letters BC (written in upper case, unspaced, without periods or full stops, and separated from the year number by a non-breaking space:" " rather than a simple space).
To indicate approximately, use the un-italicized abbreviation "c. " (followed by a non-breaking space) rather than circa, ca., or approx.